1. Field of the Invention
The present invention relates generally to solar collection systems. More particularly, the present invention relates to a solar energy collecting device that uses a two stage mirror to generate both electricity directly as well as heating a heat transfer fluid.
2. Description of Related Art
Solar energy is considered as an alternate source of energy relative to conventional forms of energy. Current solar energy collection systems are used to convert solar energy into electrical energy. The solar energy conversion system typically includes photovoltaic modules, photoelectric cells, or solar cells that convert solar energy into electrical energy for immediate use or for storage and subsequent use. Conversion of solar energy into electrical energy includes reception of light, such as sunlight, at a solar cell, absorption of sunlight into the solar cell, generation and separation of positive and negative charges creating a voltage in the solar cell, and collection and transfer of electrical charges through a terminal coupled to the solar cell.
Solar modules are primarily used in residential and commercial areas i.e. in areas served by a grid of an electric utility company. However, an advantage to solar power is that it may be generated anywhere there is sun, allowing it to be a highly mobile source of energy in remote locations.
The amount of electrical energy generated by the solar module is directly related to the amount of solar energy the cells within a module absorb, which in turn is impacted by the cell efficiency, surface area of cell coverage, and the intensity or brightness of the sunlight that is incident on the cells. Cost of a photovoltaic module increases with increased surface area coverage by the photovoltaic cells. One approach for reducing the cost associated with photovoltaic modules is via optical concentration techniques. By employing optical concentration, the cell coverage area within the laminate is reduced.
The concentrated photovoltaic modules with higher efficiency photovoltaic cells can achieve higher power densities than non-concentrated silicon modules by focusing sunlight to the photovoltaic modules using optical concentration techniques. In other words, higher concentration of sunlight together with the high efficiency photovoltaic cells leads to higher power density. However, increased solar energy concentration leads to heating of the photovoltaic module, resulting in increase of temperature of the photovoltaic material. The increase in temperature of the photovoltaic module decreases efficiency of the photovoltaic module, leading to reduced performance of the photovoltaic module. As a result, effective power generated from the photovoltaic module is limited. Moreover, there is a substantial amount of waste heat created that may be otherwise utilized.
Therefore, what is needed is a solar power generating device that may efficiently and portably generate solar power and that may also utilize heat generated by concentrated solar energy.